A wide variety of wheel assemblies have been developed for various containers such as golf bags, carriers, or, more generally, luggage, to facilitate more easily their transportation. Modem wheel assemblies typically comprise two or more wheels mounted in a rigid housing located along the bottom or base of a golf bag cover or other type of luggage. Typically, the housing and wheels have been formed of plastic or metal and either fixed to the base of the luggage, or located within a recess formed in the base.
The surfaces over which golf bag covers and other types of luggage are typically moved are often rough or uneven or "hostile" in other ways. Modem wheel assemblies often fail to provide smooth, easy, and convenient movement over such surfaces. Small, multiple-wheel assemblies along the base of a golf bag cover or other type of luggage often render the container unbalanced, resulting in tipping and shifting of contents as the wheels strike imperfections in the surface. In addition to their inherent instability, the small wheels used in modem wheel assemblies are prone to falling into cracks or holes, and getting lodged between uneven surfaces, causing additional hardship for a person pulling or pushing a golf bag cover or other type of luggage. Finally, multiple-wheel assemblies are usually more expensive to manufacture than single-wheel assemblies.
Beyond the difficulty and expense associated with the multiple wheels used in modem wheel assemblies for luggage and other transport containers, the construction of traditional wheels creates further problems. How the wheel is made and what it is made of have a significant impact on the functionality of the wheel assembly. Factors such as bulk and weight, for example, are necessary considerations in the design of luggage wheel assemblies. Traditionally, the tradeoff between a solid wheel and a hollow wheel has been weight for strength. While a solid wheel provides structural integrity and strengthens the overall wheel, it also adds weight to the container. Wheels having hollow interiors, on the other hand, reduce the weight of the wheel assembly, but are more prone to developing cracks or other flaws resulting in damage to the entire wheel assembly. Finally, cost is an additional consideration factoring into the design and manufacture of wheel assemblies used for luggage. Solid or heavily fortified wheels tend to be stronger and last longer, but are also more costly to manufacture. Hollow wheels, while perhaps being less expensive to make, demonstrate the other disadvantages noted above.
The design of wheel surfaces also affects the movement of a container over a given surface, as well as the wheel's overall structural strength and durability. An inflexible wheel surface may lend the wheel greater strength, but will also result in providing little or no traction when the wheel is used over uneven and possibly slick surfaces. A porous wheel surface, such as found with grate- or grill-type surfaces used on wheels attached to beach carts, provides better traction, but sacrifices structural strength and possibly overall wheel assembly durability when used on hard surfaces. Furthermore, such grill-type surfaces have little application outside of beach areas where sand is the predominant terrain, and their expense to manufacture decreases their desirability for use with other types of containers.
Thus, there is need, particularly in implementations involving golf bag covers or other types of luggage or containers, for a balanced, lightweight, structurally strong, and low-cost wheel assembly that improves the ease and efficiency of transport of such containers over a variety of surfaces. The present invention is directed to fulfilling some of this need.